London - World No 1 Ashleigh Barty booked her maiden place in the fourth round at Wimbledon on Saturday while Serena Williams made the second week for the 16th time.
Barty overwhelmed British wild card Harriet Dart 6-1, 6-1 while 37-year-old, seven-time champion Williams produced her most convincing display in dispensing with German Julia Goerges 6-3, 6-4.
Barty, bidding to become the first Australian Wimbledon women's champion since Evonne Goolagong Cawley won her second title in 1980, will play unseeded American Alison Riske for a place in the last eight.
She is also the first Australian woman to make the second week since 2010.
"That was really good," said Barty.
"I served really well and getting out of the love 40 game was massive.
"Incredible it is a first for me (to be in the last 16), new territory for me."
Williams reached the fourth round for the 16th time and goes on to face Spain's Carla Suarez Navarro for a place in the quarter-finals.
Eleventh seed Williams, who defeated Goerges in last year's semi-finals, is bidding to equal Margaret Court's all-time record of 24 Grand Slam titles.
"It's been an arduous year for me, so every match I'm hoping to improve tons," said Williams, who had a knee problem which affected her season.
"Every time I get out there, I try. I'm getting a really late start but all that matters is that I'm still here."
Two-time champion Petra Kvitova reached the last 16 for the first time in five years - the last time she did in 2014 she won her second title.
Czech sixth seed Kvitova defeated Poland's Magda Linette 6-3, 6-2 and will face either Britain's Johanna Konta or Sloane Stephens of the United States for a place in the quarter-finals.
On the men's side, Kei Nishikori equalled Ai Sugiyama's record of four appearances in the last 16 of Wimbledon by a Japanese player as he dismissed American journeyman Steve Johnson 6-4, 6-3, 6-2.
The leading men were due to take centre stage later with eight-time champion Roger Federer playing Australian Open semi-finalist Lucas Pouille of France.
Prior to Federer's match on Centre Court, two-time champion and third seed Nadal should have a quieter time than his previous clash, the four set win over Nick Kyrgios, against popular veteran Frenchman Jo-Wilfried Tsonga.
Mixed doubles rarely gets centre stage but British fans will wait till the bitter end as former world number one Andy Murray will partner Serena Williams against Andreas Mies of Germany and Chile's Alexa Guarachi.
"I wanted to play mixed because I've only played just about 15 matches so far this year," said Serena.
"It's such a buzz going around about me and Andy now, that I've got nervous.
"I'm ready and excited but I'm definitely nervous."
Wimbledon results on Saturday (x denotes seeding):
Sam Querrey (USA) bt John Millman (AUS) 7-6 (7/3), 7-6 (10/8), 6-3
Tennys Sandgren (USA) bt Fabio Fognini (ITA x12) 6-3, 7-6 (14/12), 6-3
Rafael Nadal (ESP x3) bt Jo-Wilfried Tsonga (FRA) 6-2, 6-3, 6-2
Kei Nishikori (JPN x8) bt Steve Johnson (USA) 6-4, 6-3, 6-2
Ashleigh Barty (AUS x1) bt Harriet Dart (GBR) 6-1, 6-1
Alison Riske (USA) bt Belinda Bencic (SUI x13) 4-6, 6-4, 6-4
Serena Williams (USA x11) bt Julia Goerges (GER x18) 6-3, 6-4
Carla Suarez Navarro (ESP x30) bt Lauren Davis (USA) 6-3, 6-3
Barbora Strycova (CZE) bt Kiki Bertens (NED x4) 7-5, 6-1
Elise Mertens (BEL x21) bt Qiang Wang (CHN x15) 6-2, 6-7 (9/11), 6-4
Johanna Konta (GBR x19) bt Sloane Stephens (USA x9) 3-6, 6-4, 6-1
Petra Kvitova (CZE x6) bt Magda Linette (POL) 6-3, 6-2
Wimbledon women's singles last 16 line-up (x denotes seeded player):
Ashleigh Barty (AUS x1) v Alison Riske (USA)
Serena Williams (USA x11) v Carla Suarez Navarro (ESP x30)
Elise Mertens (BEL x21) v Barbora Strycova (CZE)
Petra Kvitova (CZE x6) v Johanna Konta (GBR x19)
Elina Svitolina (UKR x8) v Petra Martic (CRO x24)
Karolina Muchova (CZE) v Karolina Pliskova (CZE x3)
Simona Halep (ROM x7) v Coco Gauff (USA)
Zhang Shuai (CHN) v Dayana Yastremska (UKR)